Originally Posted by wheelgrabber

I am a bit confused. The 6600 is 10 speed. The 7700 Dura-Ace derailleur is a 9 speed. The 7900 chain is 10 speed asymmetrical(be aware).

Many racers use the Ultegra. Depending upon the cassette size the weight difference is even less. The only reason the Dura-Ace weighs less is the three largest cogs are titanium versus steel. However, the titanium wear out faster.